Ammonium Problem

[sturtzzy]

so i have a 90 gallon aquarium thats been established for about a year now i only have 4 fish in the tank as of now because im waiting to figure out what the problem is out of the tap my water has about .25 ammonium and for some reason my tank has .5 to 1 after i test even after 50 to 75 % water changes also my nitrites and nitrates are 0. 

 

[fluttermoth]

Everything you're describing sounds like an uncycled tank.

Have you; changed the filter media, or washed it under the tap? Forgotten to dechlorinate after a water change? Checked your filter for blockages or bypassing of the media?

What pH is your water, in the tank, and out of the tap (after standing for 24 hours)?

 

[TwoTankAmin]

It is not possible to come to any conclusions about what might be up without a bunch more information.
 
1. What are the readings right before you do a water change?
2. What test kits are you using and are they in date?
3. What kind of fish are in the tank and what size are they?
4. What dechlor are you using, when do you add it and how soon after the water change do you test?
5. Are there live plants in the tank?
 
A good clue here is the answer to #1 above. Your ammonia can not go up adding .25 ppm of ammonia unless the tank is lower than .25 ppm tot start. Adding at .25 [ppm can not raise a tank above that level either. So to have .5-1.0 ppm of ammonia after a water change with .25 ppm water, you must have several ppm before the water change. For example: a tank with 1.75 ppm that gets a wc of 50% with .25 ppm: (1.75 ppm +.25 ppm)/2 = 1.0 ppm. To do a 75% wc and end up with 1 ppm means you must have had 3.25 ppm to start. (3.25 + .75)/4 = 1ppm.